package com.usian.admin.gateway.filter;

import com.usian.admin.gateway.utils.AppJwtUtil;
import io.jsonwebtoken.Claims;
import lombok.extern.log4j.Log4j2;
import org.apache.commons.lang3.StringUtils;
import org.springframework.cloud.gateway.filter.GatewayFilterChain;
import org.springframework.cloud.gateway.filter.GlobalFilter;
import org.springframework.core.Ordered;
import org.springframework.http.HttpHeaders;
import org.springframework.http.server.reactive.ServerHttpRequest;
import org.springframework.http.server.reactive.ServerHttpResponse;
import org.springframework.stereotype.Component;
import org.springframework.web.server.ServerWebExchange;
import reactor.core.publisher.Flux;
import reactor.core.publisher.Mono;

@Component
@Log4j2
public class AuthorizeFilter implements GlobalFilter, Ordered {
    @Override
    public Mono<Void> filter(ServerWebExchange exchange, GatewayFilterChain chain) {
//       获取请求对象和响应对象
        ServerHttpRequest request = exchange.getRequest();
        ServerHttpResponse response = exchange.getResponse();
//        判断当前请求是否为登录，如果是，直接放行  因为登录前无token拦也无用

        if (request.getURI().getPath().contains("/login/in")){
//            放行
            return chain.filter(exchange);
        }
//        获取当前用户的请求头jwt
        HttpHeaders headers = request.getHeaders();
        String token = headers.getFirst("token");
//        判断当前令牌是否存在
        if (StringUtils.isEmpty(token)){
            String json="{\"errorMsg\":\"dont have token\"}";
            return  response.writeWith(Flux.just(response.bufferFactory().wrap(json.getBytes())));
        }
        try {
//如果令牌存在，解析jwt令牌，判断该令牌是否合法，如果不合法，则向客户端返回错误信息
            Claims claims = AppJwtUtil.getClaimsBody(token);
            int result = AppJwtUtil.verifyToken(claims);
            if (result==0 ||result==-1){
//                合法，则向header中重新设置userId
                Integer id = (Integer) claims.get("id");
                log.info("find userid:{} from uri:{}",id,request.getURI());
//                重新设置token到header中 将id存到请求头中
                ServerHttpRequest serverHttpRequest=request.mutate().headers(httpHeaders -> {
                    httpHeaders.add("userId",id+"");
                }).build();//条件构造器
                exchange.mutate().request(serverHttpRequest).build();
            }
        } catch (Exception e) {
            e.printStackTrace();
//            向客户端返回错误提示信息
            String json="{\"errorMsg\":\"token is invalid\"}";
            return  response.writeWith(Flux.just(response.bufferFactory().wrap(json.getBytes())));
        }

        return chain.filter(exchange);
    }

    @Override
    public int getOrder() {
        return 0;
    }
}
